Apatosaurus sp. (S/F)

Apatosaurus is a genus of very large sauropod dinosaur in the family Diplodocidae. Its name means “deceptive reptile,” though it can also be translated to mean “headless reptile” (a name which also fits, as this dinosaur’s remains were originally discovered with the head missing). However, the intended meaning refers to the fact that its chevron bones do not look like those of other dinosaurs that were known at the time of its discovery, instead somewhat resembling mosasaur chevron bones. This dinosaur lived during the late Jurassic period between 152 and 151 million years ago in what is now western North America. Fossils have been found only in the United States, in the Morrison Formation located within Colorado, Utah, Wyoming, Oklahoma, and New Mexico. There are two known species: Apatosaurus ajax and the smaller Apatosaurus louisae. Other species have been named, but many paleontologists believe them to belong to the closely-related genus Brontosaurus, with which Apatosaurus has a long and confusing history. In its habitat, it would have lived alongside other well-known dinosaurs such as Allosaurus, Diplodocus, and Stegosaurus.

This was one of many dinosaur species discovered during the Bone Wars, an intense competition between rival paleontologists Othniel Marsh and Edward Cope. Apatosaurus bones were first discovered by Cope, but the name of the genus was given by Marsh in 1877. The remains were found in the eastern foothills of the Rocky Mountains in Colorado. The first species to be described was Apatosaurus ajax. Its species name, shared by the famous Greek hero of the Trojan War, means “of the earth.” Two years later, Marsh discovered another large sauropod, which he named Brontosaurus excelsus. No skulls for either of these animals had yet been found, and they were assumed to look like the skulls of a different sauropod, Camarasaurus.

In 1903, paleontologist Elmer Riggs realized that the first Apatosaurus ajax fossil found was not from a fully-grown adult, and that the adult form would have so many similarities with Brontosaurus excelsus that they should be considered the same species. Since Apatosaurus was named first, but its one known species was not taxonomically valid, the new official name for the species was Apatosaurus excelsus. Nonetheless, one of Marsh’s rivals Henry Osborn disagreed and labeled a famous museum specimen as Brontosaurus, making this name better known to the general public despite its invalidity.

Profile of an adult Apatosaurus ajax

In 1909, a skull belonging to this animal was finally found by Earl Douglass; it was assigned to a new species, Apatosaurus louisae, named after philanthropist Andrew Carnegie’s wife Louise Carnegie. There was great debate in the paleontological community as to whether this species should be considered an Apatosaurus or used to resurrect Brontosaurus, as well as the true appearance of the skull of Apatosaurus excelsus. Not until the 1970s was this issue resolved, with paleontologists agreeing that the skull discovered in 1909 truly did represent what the animal’s head really looked like. Confusion and debate regarding the identity of these animals continued for decades, with Dr. Robert Bakker arguing in the 1990s that both Apatosaurus (in the form of A. louisae) and Brontosaurus (in the form of B. excelsus) should be considered valid.

Other scientists eventually came to similar conclusions. In 2015, a study by Emanuel Tschopp, Octávio Mateus, and Roger Benson found that there were enough differences within Apatosaurus to warrant classifying them into different genera, resurrecting Brontosaurus. Among the most notable differences are the wider and stronger neck of Apatosaurus compared to Brontosaurus. There are two species of Apatosaurus recognized today, the larger A. ajax and smaller A. louisae, while there are now three species of Brontosaurus: B. excelsus, B. yahnahpin, and B. parvus.

Right hind foot print of an Apatosaurus provided by the Dinosaur Protection Group. Note that it is identical to an InGen Brachiosaurus hind foot print, and possesses an extra toe.

The history of this animal in de-extinction is equally muddy. While International Genetic Technologies documents state that it had obtained Apatosaurus DNA from Jurassic amber and reconstructed 57% of the genome by 1993, there is no indication that this animal was cloned. Skeletal remains found on Isla Sorna in 1997 have been attributed to “Apatosaurusexcelsus, which as of 2015 is now widely considered to be a species of Brontosaurus. However, in around 2005, InGen succeeded in cloning animals that are still today said to be Apatosaurus: based on their size, they are probably Apatosaurus ajax. Whether InGen succeeded in cloning both Apatosaurus and Brontosaurus, with both being classified as Apatosaurus until 2015, is unknown. The true identity of the skeletal remains found in 1997 is also a mystery.


Among the larger and longer of the dinosaurs, Apatosaurus reaches lengths of 69 to 90 feet (21 to 27.4 meters). It stands around 16 feet (4.9 meters) high at the hips, and does not usually hold its head particularly high; at its highest, this animal usually reaches twenty feet (6.1 meters). This massive sauropod can weigh between 19,998 and 80,819 pounds (16,420 and 36,658.7 kilograms), and in terms of both size and mass, InGen’s specimens routinely grow to the larger end of this scale. About half of its body length consists of the tail, with the remaining length made up of the neck and back in equal measure.

Note that the length given on this Jurassic World display (forty-nine feet) does not include the complete tail. A matured A. ajax averages seventy-five feet long when the tail is included.

While it is among the most primitive diplodocids, Apatosaurus already has many of the features common to its kind, beginning with the head. Its skull shape is long and squarish, with a mouth full of many chisel-shaped teeth. Fossils suggest that it cannot chew, though InGen specimens have sometimes demonstrated a limited chewing ability (not as advanced as InGen’s Brachiosaurus, where this ability is also abnormal). The tongue is not particularly mobile, as with many sauropods, and is rounded and pinkish. The eyes of Apatosaurus are circular, with a distinct iris and white sclera. All Apatosaurus seen so far have had blue irises, though like other animals, different eye colors are probably possible. This dinosaur’s eyes are noticeably heavy-lidded, giving it a “tired” appearance. Its nostrils are located on the snout, rather than the forehead as in some illustrations.

The neck of Apatosaurus comprises about a quarter of its total body length and is wide and deep due to the shape of its cervical vertebrae. These vertebrae are bifurcated, with tall neural spines framing a trough in between. This allows for strong muscles to support the neck, and internal air sacs help to reduce its weight. Not only are its vertebrae stouter and sturdier than some of its relatives, it also has long cervical ribs, which together with the overall shape of its vertebrae and ribs gives its neck a triangular profile when viewed from the front. On the other hand, the ten pairs of dorsal ribs are not attached to its backbone, making its body flexible. When walking, it keeps the base of its neck more or less parallel to the ground, with the head raised up to about twenty feet off the ground as described above. The head faces slightly downward when at rest. The neck is flexible enough to bend into a U-shape laterally, and can be arched to reach the ground without bending the legs. This allows the animal to feed at the level of its feet, and to drink water from lakes and rivers.

A close inspection will reveal that this apatosaur’s hind feet are polydactyl, with five digits; this is observed in some of InGen’s specimens.

This sauropod’s bulk is supported by four robust pillar-like legs, with the rear pair being a little longer than the forward pair. Like other sauropods, Apatosaurus has only one clawed toe on the front feet, with the other toes reduced. The hind feet have four clawed toes, one more than the original animal did, with the innermost toe bearing the largest claw. It can rear onto its hind legs, permitting it to access food higher off the ground, but it cannot walk on two legs. Generally this is a slow-moving animal, lumbering at speeds of only five miles (8 kilometers) per hour, but it can run at 12 to 19 miles (20 to 31 kilometers) per hour for short distances if pressed. Apatosaurus has a deep chest due to its long ribs, setting it apart from other diplodocid sauropods.

Along with its neck, the most noticeable feature of Apatosaurus may be its lengthy whip-like tail, which makes up about half of its total length. Held in parallel with the ground, this tail counterbalances the weight of the neck. Apatosaurus can be told apart from other, more advanced diplodocids by the shape of its tail. The caudal vertebrae are much shorter than the rest, meaning that the tall internal spines supporting its neck and back are absent on the tail. Because of this, the tail is far more slender than many other diplodocids, though it still tapers to a thin and flexible section at the end. Its tail can be cracked like a bullwhip, with the tip breaking the sound barrier.

Its skin is covered in smooth, flat scales, without any raised spines or scutes visible. There is some speculation that prehistoric Apatosaurus may have borne spines down their backs or on the undersides of the necks, but InGen’s apatosaurs have no such features. Its scaly skin is wrinkled due to fat and muscle underneath, which may give it a ridged or lumpy appearance.

Like most sauropods, this dinosaur is not very brightly colored, at least not to the human eye. Since dinosaurs can see ultraviolet light, it may appear more colorful to dinosaurian vision. Its color within the visible light spectrum gives it a variable gray color, with some being shaded tan or pale green. It is usually darker on its back, and lighter on the underside of its neck, but it is not as distinctly countershaded as some other sauropods. Apatosaurus has vertical stripes, which are thin and triangular in shape with the widest on the back. The shade of its stripes varies from very pale in some animals, almost disappearing into the otherwise uniform body color, to cobalt blue or sandy tan in others. Length and orientation of the stripes also varies. This may be related to age, sex, or health, but exact details are poorly known.

Juvenile Apatosaurus, Isla Nublar (12/22/2015)

The juvenile Apatosaurus shows some marked physical differences from the adult aside from just size. Its neck and tail are proportionally shorter, and the tail thicker. There is a greater disparity between the hind and forelimbs, and the snout in early juveniles is noticeably blunter. Colors on the juvenile are mostly duller and lighter, with the striping becoming more noticeable as the animal reaches adolescence. It reaches adulthood in ten years, and its size peaks out in fifteen years. This is much faster than fossil evidence suggests; some paleontologists believe that its natural growth rate would lead it to reach lengths of twenty-five feet within fifteen years and would not become sexually mature until its late teens or early twenties. InGen’s specimens most likely grow faster due to genetic modification, since this would make them park-ready much earlier. Reaching maturity by age ten was predicted in sauropod studies of the 1990s, but has been challenged by more recent work, which suggest maturity is reached at 21 years.

The full lifespan of this animal is known, but sauropods tend to be fairly long-lived. Some paleontologists have estimated that Apatosaurus could live for up to seventy years. However, most fossil animals died in their late twenties or early thirties. It probably lives much longer in captivity.

Sexual Dimorphism

So far, there is no reliable way to distinguish male and female Apatosaurus, although it has been suggested that the more vividly-colored animals are males.

Preferred Habitat

The dietary requirements of Apatosaurus are the deciding factor in choosing a habitat. While its bulk prevents it from easily navigating within dense forests, it needs to have plant life around, and so generally prefers grasslands interspersed with islands of trees. In its native Jurassic period, it lived near gallery forests, which sprung up along riversides in otherwise semiarid, prairie-like environments. Their habitat in prehistory had distinct wet and dry seasons. It flourished here, becoming one of the most common sauropods. Because of its massive size, it tears down trees as it feeds, expanding the size of grasslands in its habitat. Uprooted trees, and trees stripped of leaves during the summer months, are obvious signs of Apatosaurus activity.

In the Jurassic period, this dinosaur was exclusive to warm climates, and thrives in the tropics today. However, InGen modified its physiology to help it survive in the modern world, and it is now able to use its gigantic bulk to sustain a high enough internal body temperature to withstand cold temperatures. It can survive in chillier parts of the world than its ancestor would ever have seen.

Muertes Archipelago

InGen originally worked on the Apatosaurus genome at their research facilities on Isla Sorna, and possibly attempted to clone the species there. However, they had only obtained 57% of the genome, meaning the viability was barely more than half. It is still technically possible to clone an animal with this kind of viability, but the results are usually less healthy and do not survive long. InGen documentation shows that no Apatosaurus were known to be alive on Isla Sorna at the time the whole Muertes Archipelago was abandoned in 1995 due to Hurricane Clarissa. A report published in 1994 and including data from 1993 makes no mention of living or recently-dead Apatosaurus.

During the 1997 Isla Sorna incident, survivors briefly discovered the disarticulated skeletal remains of what appear to be two adult apatosaurs near the Workers’ Village. This is the only evidence that InGen succeeded in cloning this dinosaur before 2005. If so, these two specimens probably hatched in the mid-to-late 1980s in order to reach skeletal maturity, but had died before 1993. It is most likely that no other specimens had been bred yet. Some remains in the Embryonics facility have been suggested to be Apatosaurus embryos, indicating InGen may have been working on this species up until the time of Hurricane Clarissa.

The skeletal remains found in 1997 are popularly believed to belong to Brontosaurus excelsus, which at the time was classified as a species of Apatosaurus. This would mean that InGen obtained the DNA of two different genera of apatosaur. If that is the case, either InGen never succeeded in recreating Brontosaurus again, or that their later Apatosaurus used some of the old Brontosaurus genome to fill in their gene sequence gaps.

Isla Nublar

Sometime around late 2004 or early 2005, the first Apatosaurus ajax were hatched at Jurassic World on Isla Nublar, reaching adult size by late 2014. They had not yet been hatched by early September 2004, and were not yet on exhibit by the time the park opened at the end of May 2005; the apatosaurs became a part of the park sometime after this. The earliest date given for one of these animals to have hatched was 2010, since an eight-year-old female was said to be still living on Isla Nublar as of May 15, 2018, but these animals take about ten years to mature and there were fully-grown adults on the island as of November 2014.

When juvenile apatosaurs grew old enough to leave the hatchery, many of them were introduced to the Gentle Giants Petting Zoo where visitors could interact with them. Once they grew large enough, they would be transported from the petting zoo to the island’s large central valley, where they would become a part of the attractions there.

Apatosaurus was a featured attraction at the Cretaceous Cruise and the Gyrosphere, and was able to travel back and forth between these areas through Gallimimus Valley. As of December 22, 2015, there were thirteen adults living in the Gyrosphere area and two adults plus one subadult living near the Jungle River. Three juveniles were present in the petting zoo. On that day there were also at least six apatosaurs traversing Gallimimus Valley, but these animals were ambushed and killed by the escaped Indominus rex, putting a noticeable dent in the apatosaur population. Due to this incident, Jurassic World was closed down permanently, allowing the apatosaurs to freely roam across the island. It is unknown what happened to the juveniles in the petting zoo; they may have been released by their caretakers into the valley.

An Apatosaurus killed during the Jurassic World incident, Isla Nublar (12/22/2015)

After the park’s closure, the apatosaurs moved gradually northward, with the bulk of the remaining population settling in the foothills of Mount Sibo. This volcanic mountain became active in early 2017, with pressure slowly building beneath the island; increased magnetic activity acted as a beacon to Isla Nublar’s dinosaurs, the apatosaurs included. No juveniles were sighted after 2015, and with an imbalanced predator-to-prey ratio on the island, it is possible that the adults did not succeed in rearing any new offspring.

On June 23, 2018, a total of thirteen Apatosaurus were seen near Mount Sibo, with a further two captured and transported off the island via the S.S. Arcadia under the direction of Ken Wheatley. The skeletons of two subadults, completely stripped of flesh and sun-bleached, were seen near Radio Bunker 02-17 just southeast of Mount Sibo. This means that there were a total of at least twenty-three adults and subadults as well as at least three young juveniles before the 2015 incident, and at least seventeen adults and subadults on Isla Nublar between December 22, 2015 and June 23, 2018. On that day, Mount Sibo experienced a violent and explosive eruption which drove the apatosaurs toward the east. Here, they were forced to choose between suffocating in a cloud of burning ash or plunging hundreds of feet into the ocean, where they would either drown or simply die on impact with the water from such a height. Animals living in the south of the island may have fared better for a little while, but with the eruption destroying most or all of the forest on Isla Nublar, this species is now almost certainly extinct there.

One of the Apatosaurus removed from the island was held in Container #31-1012-2647 (Cargo #64222) and cosigned by Joel Melior, logged into the Arcadia‘s manifest at 13:50. It was weighed at 21,530 kilograms, a good mid-sized weight for this animal.

Mantah Corp Island

During the years Jurassic World was in operation, Mantah Corporation was constructing and operating a facility of its own, located on the privately-owned Mantah Corp Island. Genetic samples and live specimens of several organisms were obtained, allowing Mantah Corp to begin breeding creatures of its own. Apatosaurus specimens would have been obtainable, but there is currently no evidence they were in possession of any.

Biosyn Genetics Sanctuary

After de-extinction became an open-source technology, these animals began appearing globally. Some were escapees from the incident in 2018, but others were bred by various interested parties. Due to the increasing populations of wild dinosaurs, Biosyn Genetics was authorized to capture and contain the animals wherever they could. The most prominent containment facility they controlled was the Biosyn Genetics Sanctuary, located in the Dolomite Mountains of Italy.

Apatosaurus was one of the species housed there, though none were seen in late 2022 before the United Nations took over operations. This may mean that no Apatosaurus arrived to the sanctuary valley while Biosyn was managing it. Juveniles are now known in the valley, indicating a breeding population.

Black market

It is unknown if any Apatosaurus fell victim to poachers before the 2018 eruption of Mount Sibo which drove them to extinction on Isla Nublar. If any were captured, even fairly well-equipped poachers would only have been able to retrieve juveniles, and it is unlikely that they would fare well in the hands of most exotic-animal owners due to their vast appetites.

On the night of June 24, 2018, at least two adult Apatosaurus ajax were delivered to the Lockwood estate near Orick, California via the S.S. Arcadia after being removed from Isla Nublar. They were held at the estate in the sub-basement laboratory overnight with the intent to be sold at auction; this plot was not completed due to the auction being disrupted by animal rights activists. The apatosaurs were released from captivity by Maisie Lockwood during the night to save them from a hydrogen cyanide leak. These animals, the last of their species, fled into the wild.

Since these events, animal trafficking and illegal breeding has moved these species around the world. Though none were sold in 2018, their DNA quickly entered the black market; all ancient DNA is highly valuable and the genes of this huge sauropod are no exception. Although moving the adult animal itself is a laborious process, it is fairly easy to move juveniles before they hit their growth spurt, or to simply cart around samples of genetic material. To find these specimens, one might look in covert places such as the Amber Clave night market in Valletta, which is a major hub of de-extinct organism trade.

Wild populations

Evolving during the Jurassic period, this was one of many huge sauropods to inhabit western Laurasia around 152 million years ago. Its habitat encompassed what is now North America, which during the late Jurassic had rifted apart from the half of Laurasia that would become Eurasia. Its environment was low-lying floodplains and forests, and it experienced wet and dry seasons. After around one million years, it is believed to have become extinct as its environment was in a state of perpetual change; new species took its place. Apatosaurus DNA samples were recovered more than one hundred fifty million years later by scientists who used these samples to clone the animal, bringing it to life again.

During the night of June 24, 2018, a small group of apatosaurs (possibly as few as two) were brought illegally to Orick, California to be sold. They were released into the wild during the night. Since then, their populations have grown, bolstered significantly by illegal captive breeding. Many adult animals seen in the wild today are likely former captive specimens who were turned out after growing too large. They were commonly seen in the U.S. state of Wyoming as of early 2022, though many of them were also seen farther west, and some are known to the north along the Missouri River. A pair of adults were discovered in a small Northern California logging town between the Sierra Nevada and Cascade Mountains in the late winter of 2022, and were relocated by local mill workers. A small herd is also known to inhabit woodlands near Lake of the Woods, Oregon; they encountered the oldest surviving Tyrannosaurus before its relocation in the spring of 2022. Jurassic World Evolution 2 depicts Apatosaurus as migrating into Yosemite National Park in California, where they can be seen living in the wild in small herds. Outside the United States, Apatosaurus has also been sighted in Canada, particularly in Ontario. A herd resides near woodlands near Toronto and has regularly caused traffic jams on the Kingsway since November 9, 2021 when they were first reported to the Department of Prehistoric Wildlife. The northernmost population is located near Disko Bay in Greenland. In addition to extreme cold, these apatosaurs must contend with food scarcity in order to survive.

Human intervention has brought this animal to new continents as well. The CIA’s dinosaur tracking division is monitoring a population near Peru’s Apurímac River. Two adults were sighted in the late winter of 2022 in Gesäuse National Park, located in Nogerwald, Austria. The first apatosaurs sighted in Europe were identified by the CIA in 2021, located on the southern coast of France. Fewer are known in Africa, with just one population currently confirmed near the southern parts of the Kwango River in Angola.

Asian specimens are also known. On May 27, 2022, a single apatosaur was reported in the city of Dehradun, India. Like the pair seen in Austria, this one was brought to India by human intervention. Likewise, a population known from the southern parts of China’s Mekong River were introduced by humans. They are found as far north as the Russian tundra, where they can be found between the Central Siberian Plateau and the Lena River.

Behavior and Ecology
Activity Patterns

This dinosaur is diurnal, active during the daytime. So far it has never been sighted moving about at night, probably conserving its energy. It spends most of its day feeding, traveling from one food source to another, and intermittently heads for water sources to drink and bathe. Apatosaurus socializes throughout most times of the day while feeding and migrating. Unlike its neighbor Brachiosaurus, it does not habitually rest during the heat of midday and may be seen active at any time during the day.

Diet and Feeding Behavior

Like all sauropods, Apatosaurus is an herbivore, browsing chiefly on ferns, cycads, and the branches of conifers such as the giant sequoia (Sequoiadendron giganteum). It has also been known to eat leaves from other types of trees, generally preferring softer foods such as foliage, shoots, and fruits. Fossil evidence suggests that its diet includes cycadeoids, seed ferns, and algae. It sometimes eats bracken ferns, which can become toxic in accumulation. Many of the plants it feeds on grow at the ground level; some paleontologists have theorized that it may also feed on aquatic plant life found in the rivers where it drinks.

Apatosaurus rearing onto its hind legs to feed from a sequoia tree

Because of this dinosaur’s enormous size, it needs to eat vast quantities of food to fuel its body, so it spends most of its time either browsing on plants or looking for food sources. The purpose of its long neck is to reach foods that smaller herbivores cannot, enabling it to efficiently compete for resources. With this neck, it is able to reach higher in trees or farther away from its body. This gives it an advantage that has shaped its evolution.

In order to feed from trees, Apatosaurus can also rear onto its hind legs to reach even higher. Here, the claws on its front feet come in handy; they can be used to grip tree trunks, either to stabilize the animal as it feeds, or to push less sturdy trees down to the ground. Apatosaurus has peg-like teeth that it uses to strip leaves from plants. Due to genetic modification, modern apatosaurs can chew to a limited degree, but still prefer to swallow larger pieces whole rather than masticate their food into a pulp. They probably swallow gastroliths to aid in digestion. Massive amounts of dung are produced by these dinosaurs, with piles of droppings exceeding the height of an adult human.

Jurassic World: Evolution presents its favorite food source as conifers, while it also enjoys ginkgoes and tree ferns. It cannot digest pawpaws, mosses, or horsetails. The game’s sequel portrays it feeding chiefly on tree foliage.

Social Behavior

This dinosaur lives in small herds and is usually not seen alone. Like most sauropods, it has only limited intelligence, and this restricts the amount of social behavior it shows. Rather than establish a set territory, Apatosaurus migrates about in search of food sources, crossing over grasslands in search of forested land. Traveling in small groups not only ensures that there are more eyes looking out for food or potential hazards, it also provides emotional comfort and staves off loneliness.

To communicate, this animal mainly uses body language; it is one of the quieter sauropods. The movements of its neck and lengthy tail are probably communication. It does also vocalize, including a small number of loud sounds when it needs to rouse its companions. Herds may include both adults and younger animals; fossil evidence demonstrates that intergenerational herds were commonplace in prehistoric times. Limited physical contact is involved with their interactions compared to other sauropods; in Jurassic World: Evolution 2, members of the same herd will sometimes nuzzle snouts, but other than this they interact mainly using visual cues and vocalization.

Apatosaurus has some degree of emotional intelligence despite its fairly small brain. There is some evidence that they will defend one another even in dangerous situations.

So far, no hierarchy has been noted in Apatosaurus social groups. Unlike Brachiosaurus, which has herds led by a dominant individual, life among Apatosaurus appears to be egalitarian. By keeping to smaller groups and living in flourishing environments, this dinosaur reduces intraspecific competition and ensures that there is enough food to go around. The neck of this dinosaur is muscular and strong, which some scientists believe makes it suitable for “neck-wrestling” matches similar to those of modern giraffes. This would probably occur between males competing for a mate, and since most (but not all) animals at Jurassic World were female, this has not yet been observed directly.

Some amount of empathy and loyalty between members of the same herd seems to occur in Apatosaurus, with the animals defending one another from predators. When the escaped Indominus attacked an apatosaur herd in Jurassic World, six of the animals died in nearly the same place, with only the last animal to die being farther away. This suggests that, rather than flee the threat after the first apatosaur was ambushed, the remaining herd members stood together. Unfortunately, having never faced any challenge to their survival before, the Apatosaurus‘s refusal to leave their wounded or fallen fellows doomed them to a bloody death.


The eggs of Apatosaurus have not yet been seen, but sauropod eggs are well-studied. They are generally large (some of the biggest of all dinosaur eggs) and round, laid in excavated nests and probably insulated with mud or plant matter. According to Jurassic Intel’s Guide to Dinosaur Eggs, the eggs of larger dinosaurs such as sauropods incubate for around a year before hatching. Fossils demonstrate that sauropod eggs are laid in large numbers. The courtship and mating practices of Apatosaurus specifically have not been observed, though its distant relative Mamenchisaurus has been described mating. In this relative, the mating process is fairly quick due to the immense size of the animals involved, and is initiated by an equally brief courtship routine. Like most dinosaurs, its external reproductive system takes the form of a cloaca located near the base of the tail.

Apatosaurus can be reared without the presence of adults of its own species, but requires protection until it grows large.

Likewise, the rearing behaviors of Apatosaurus can only be inferred from their relatives, since none have yet been witnessed raising young in the wild. Brachiosaurus guards its eggs, contrary to what many paleontologists assumed, and protects its young for years after hatching. However, it does not attend to the young of other herd members, nor will it adopt orphaned brachiosaurs. Apatosaurus may exhibit similar behaviors, protecting its own eggs and offspring but not providing care for juveniles that are not its immediate family.

Fossil evidence suggests that Apatosaurus reached sexual maturity in its late teens or early twenties, but InGen’s specimens grow faster, reaching their full size between ten and fifteen years old. This means they can probably reproduce at an earlier age than their ancestors, making their population growth rate more efficient for a park environment.


While it lives in social groups, Apatosaurus is one of the less vocal sauropods, a stark contrast to species like Brachiosaurus. Most of its communication appears to be body language, involving movements of the neck and tail (this has also been seen in Mamenchisaurus). The tail can not only be waved around to gesture to other apatosaurs; it can also be cracked like a whip, breaking the sound barrier with a loud noise that can be used as a threat display. Because there is usually fairly little intraspecific aggression in Apatosaurus, this is more useful in communicating with other species: the loud crack is universally recognizable as a warning to keep back. While traveling, the tail is swished back and forth to signal to those behind.

This is not to say that Apatosaurus is mute. It does vocalize to communicate, making a limited range of grunts, moans, and growls to express itself. Some of its vocalizations are louder and more musical wails, quite similar to those of Brachiosaurus; these are its most social calls, and since they are so much like brachiosaur calls, it is probable that these two sauropods can communicate with one another. This may have even been the case in the ancient past, since they inhabited similar regions during the same time period. Other than these social vocalizations, the meanings behind Apatosaurus sounds are poorly studied.

Ecological Interactions

As with many sauropods, the main defense Apatosaurus has against danger is its sheer bulk, and as an adult there are few animals that can threaten it. Fossil evidence suggests that it routinely survived attacks from predators such as Allosaurus. Since an apatosaur faces few threats, it has little need to be aggressive, and so is generally relatively safe to be around. If it feels as though another animal may be a threat, a loud supersonic crack from its whip-like tail is usually enough to deter most predators from attacking. The tail tip is actually fairly thin and therefore makes an inefficient weapon, as it would break easily, but the size of an adult Apatosaurus means that it can easily crush many threats underfoot should they be foolish enough to attack.

Normally slow, the Apatosaurus can move quickly for short bursts when frightened.

Unfortunately, the first generation of wild apatosaurs was raised in captivity and therefore was never exposed to predators. When Jurassic World fell in late 2015, six Apatosaurus were among the dinosaurian victims of the escaped Indominus rex. They had never encountered a predator before, let alone one that could camouflage itself, and were ambushed. All of them were slaughtered, dying from shock and blood loss after sustaining heavy gouges to their flanks and necks.

Juveniles are fairly easily threatened by predators of all sizes. Since they were brought back from extinction, this sauropod has faced its natural predator Allosaurus again, as well as threats it never would have encountered such as Tyrannosaurus, Baryonyx, Carnotaurus, and Teratophoneus. Of these, Tyrannosaurus was probably the most likely to attack an adult apatosaur and succeed, while the fish-eating Baryonyx and comparatively small Teratophoneus would be less dangerous neighbors. Still, even the biggest threats could usually be driven away with a swipe from the whip-like tail. It also lived in areas inhabited by Pteranodon and Velociraptor, which could never threaten an adult, but could easily overpower and eat a juvenile. Other carnivores in its territory near Isla Nublar’s Jungle River included Suchomimus and Metriacanthosaurus; they too would be threats to juvenile apatosaurs, though the Suchomimus mainly eats fish. More poorly known is its relationship to the omnivorous theropod Gallimimus, an opportunist that normally feeds on small animals and plants and is usually non-threatening.

The smallest carnivore it is known to have lived near is Compsognathus. Rather than being a threat, the minuscule compies would have benefited the apatosaurs by eating insects and other pests, as well as consuming carcasses and dung that would otherwise become sources of disease. The dung produced by such huge herbivores, as well as carcasses from fallen individuals, massively benefits the compies and other scavengers such as birds and insects as sources of nutrition. When an apatosaur dies, it creates a small temporary ecosystem around its body involving all manner of small detritivores such as flies, corvids, and other animals.

Living apatosaurs can be threatened by disease, as well as predators. While (according to Jurassic World: Evolution) they are immune to the common cold, they were bitten by mosquitoes and other parasites during the Jurassic period, and probably are similarly afflicted today. Biting insects can expose their victims to a host of potentially fatal diseases, taking down these giants from the inside. Even their diet can sometimes put them at risk; if they eat too much of the bracken fern, they can become poisoned.

The feeding strategies of sauropods enable them to live alongside large numbers of other herbivores by reaching foods their neighbors cannot. Apatosaurus demonstrates niche partitioning with its fellow sauropod Brachiosaurus, feeding lower to the ground while Brachiosaurus browses mainly at the tops of trees. Similar situations exist among the other herbivores in its habitat: it can cohabit successfully with its ancient neighbor Stegosaurus, the hadrosaurs Parasaurolophus and Edmontosaurus, the pachycephalosaur Stygimoloch, the ankylosaurs Peloroplites and Ankylosaurus, and the ceratopsians Triceratops, Microceratus, and Sinoceratops without difficulty. The biggest threat among the herbivores would be Triceratops, since this territorial animal is often aggressive toward the juveniles of other species and may bully them to the point of starvation.

Being such a large animal, Apatosaurus is a force of nature in its ecosystem and shapes its habitat rather than adapt to it. As this animal feeds, it tears down trees and tramples smaller plants, creating grassland and determining where the forest ends. It feeds on a wide range of plant life, mostly those that grow closer to the ground, though it can easily rear up to eat higher tree branches or push trees down. Of course, such size is a double-edged sword; Apatosaurus depends on the health of local flora to survive and must eat vast quantities to get the energy it needs. If plants dwindle away, these sauropods will suffer. On the other hand, if plants are healthy, Apatosaurus will eat freely and produce large amounts of dung which fertilizes the land. Ultimately, this animal is a major force in its environment, but is still dependent upon the forces of nature for its survival like any living thing.

Cultural Significance

Apatosaurus is an extremely well-known dinosaur, famous representative of both the sauropods and the Jurassic period on the whole, and is an absolute must for any complete dinosaur encyclopedia. It is commonly depicted in films and paleoart. In works that are meant to be educational, Apatosaurus is often described as the “real” alternative to the more famous Brontosaurus, owing to the fact that for a long period of time the two were considered synonymous. In 2015, though, some paleontologists suggested that they should be considered different genera after all. Not all pop culture has caught up to the science, unfortunately. While paleontologists and paleoartists can discuss or depict both genera of sauropod validly, Apatosaurus remains more popular among scientists and science enthusiasts because it is the older of the two names and therefore less controversial. Should the two dinosaurs be lumped together once more, Apatosaurus would remain the valid name.

As one of the more famous dinosaurs found in the American West, Apatosaurus has become known as one of the “Wild West” dinosaurs in the United States. Its whip-like tail further enhances its association with classic Old West imagery.

According to Universal Studios, Apatosaurus is the dinosaur of the Virgo astrological sign (August 23 – September 22).

In Captivity

This was the second sauropod successfully kept in captivity, after Brachiosaurus. It was one of the mainstays at Jurassic World, drawing in tourists to view it from the Gyrosphere, Gallimimus Valley Tour, and Cretaceous Cruise rides. Juveniles were popular at the Gentle Giants Petting Zoo, where young children could interact with them up close and in person. Apatosaurus is one of the most well-studied and famous sauropods, though perhaps better known through its confusion and/or synonymy with Brontosaurus, and so was a must-have for the world’s only de-extinction park.

Of course, the biggest challenge to keeping a sauropod in captivity is providing for its diet, and this restricted both the number and habitat of this animal. In order to ensure it had enough food, water, and roaming space, the entire central valley had to be open to it. Furthermore, it appears that this species replaced Brachiosaurus in that range, with InGen only able to provide for one sauropod species at a time in the same attraction. The effort into keeping Apatosaurus appears to have paid off, though, bringing crowds to the park for the chance to see this beloved dinosaur.


Together with Brontosaurus (since 2015), this dinosaur has been classified in the family Apatosaurinae, which gets its name from this genus. It is a well-studied animal with a long history in American paleontology and was one of the many animals named during the Bone Wars; in particular this genus was named by Othniel Charles Marsh. Some quite excellent fossils have been found, though complete skeletons are rare. This dinosaur was a major force in the ecosystem in which it lived during the Jurassic period; it was one of the largest herbivores in its habitat, and appears to have been reasonably common with several different species existing. Fossils of juveniles have been found, which have informed scientists on details of sauropod ontogeny and growth rates; this has revealed that they grew to adulthood in ten to twenty years, and average specimens seem to have lived into their late twenties.

Most famously, Apatosaurus is among the most publicly-known examples of genus synonymy. It was named before Brontosaurus, but later the two genera were thought to be the same. In this case, Brontosaurus was what is known in taxonomy as a junior synonym: a name made invalid by the fact that an original name takes precedence. However, not all scientists always agreed with the synonymy. In 2015, an extensive study claimed that the two should be separate after all, and this proposal has become accepted by many paleontologists.

Since the late 1990s, scientists have used Apatosaurus fossils in physics simulations to test the function of diplodocid tails. Their anatomy had long suggested that they could be swished at high speed, but in 1997 simulations performed by Philip J. Currie and Nathan Myrhvold revealed that an Apatosaurus tail could generate a sharp cracking sound like a bullwhip at volumes of up to 200 decibels.

Apatosaurus has also gained attention in the Genetic Age, not necessarily for the paleontological value of de-extinct specimens but for the genetic research that they lend themselves to. While this species (the third confirmed to be added to InGen’s genetic library) has been altered from its original form and thus is of questionable paleontological importance, it is a very successful de-extinct sauropod and has provided geneticists ample opportunity to study the genomes of these animals. Without such research, Jurassic World could never have succeeded.


In the years following the fall of Jurassic World, this and other dinosaur species became embroiled in the Mount Sibo controversy. The Dinosaur Protection Group often used imagery of Apatosaurus to garner public support for rescuing the dinosaurs from extinction, knowing that this creature was greatly endeared to many people. It held particular significance to the DPG’s founder Claire Dearing, whose journey to becoming an animal rights activist was put back on track during the 2015 incident when she and animal behaviorist Owen Grady encountered and comforted a wounded, dying Apatosaurus. The undeserved fate of this unfortunate animal set Dearing back on the path to political activism that she had forgotten during her tenure as Jurassic World’s Operations Manager.

While the DPG was not enough to sway the conservative American government to rescue the dinosaurs, an illegal operation in 2018 did secure at least two adult Apatosaurus with the intent to sell them on the black market. It is unknown which of Eli Mills‘s customers requested them. No Apatosaurus are confirmed to have been sold; instead, they were released into the wild after the auction was disrupted.


Such a famous dinosaur draws massive crowds when kept in captivity, making it a potential moneymaker, but its upkeep is also expensive. Sauropods as tourist attractions are difficult since they need large space, huge quantities of food, and often must be kept in herds. Jurassic World succeeded with this, but it is unlikely a more modestly-funded facility would have been able to.

Apatosaurus is also potentially valuable as a source of biological materials usable in science and agriculture. Its relative Brachiosaurus is used for its dung, which makes excellent fertilizer, and Apatosaurus dung is most likely useful this way as well. All de-extinct animals also have biopharmaceutical properties unlike those in modern naturally-occurring animals, for which Apatosaurus was captured for black market sales in 2018 by hunter Ken Wheatley. His employer, the Lockwood Foundation’s manager Eli Mills, intended to sell them to finance Henry Wu‘s research; while none are confirmed to have been sold, it was expected that they would pull in millions of dollars.


Since this animal grows so large, it has little need to be aggressive like more medium-sized herbivores. Instead, it generally ignores small animals like humans, at best expressing curiosity. Still, caution should always be taken around a large animal, even one that is typically passive in nature; it is easily capable of crushing a person to death either on purpose or by accident. We recommend observing all sauropods from a distance to avoid being flattened or struck by falling debris that it dislodges while feeding. Apatosaurus is quite big and can be seen from far away, so there is really no need to get dangerously close to it.

It is normally slow-moving, but can briefly run when agitated. When it runs, it may move faster than you expect such a bulky animal to do. This is one of the main reasons to keep a respectable distance from it; underestimating its speed and power could be fatal. Keep extra distance if there are young or eggs nearby. InGen scientists have determined that many sauropods practice parental care, so an Apatosaurus will protect its offspring. If an Apatosaurus does charge, your only real defense will be to flee. It is powerful enough to push through any obstacles, so do not bother hiding in a vehicle or behind trees and rocks; it will knock over most things in its way. Instead, we suggest running perpendicular to its path, and taking shelter in a very sturdy building or a small crevice where it cannot follow. Once you are out of sight, wait long enough that it forgets you are there or decides you are not dangerous, and then leave the area quickly. If no safe shelter is available, try concealing yourself in tall grass or bushes, especially those that conceal you from above. As a last resort, get down on the ground and look as uninteresting and harmless as you can.

Remember that being behind an Apatosaurus is no guarantee of safety. It is well-equipped to defend itself from large theropods that attack from behind using its tail. At top speed, a strike from an Apatosaurus tail could severely wound or even kill a human-sized animal. If it knows you are there and does not like you sneaking up from the back, it may give a warning “shot” with its tail, which you will hear as a loud cracking noise. Get back immediately if you hear this: it means the apatosaur has decided you are too close.

Behind the Scenes

This dinosaur was initially planned to appear in earlier films. In Jurassic Park, it would have appeared as a carcass being fed upon by the tyrannosaur during a scene in which Alan Grant and the Murphy children take a raft down the Jungle River; the name Apatosaurus is also mentioned in the film’s script during Scene 49 as one of the embryos stolen by Dennis Nedry. However, no apatosaur embryo appears in the film. It was intended to appear in The Lost World as well, though its role was given to the larger Mamenchisaurus.

village07Apatosaurus is confirmed to be on Isla Sorna due to The Lost World Official Souvenir Magazine identifying the several skeletons spotted just outside of the Workers’ Village as belonging to an “apatosaur”.

“Everywhere, the land is is dotted with dinosaur skeletons. Some are huge apatosaurs, while others are smaller herbivores of many different species.” (The Lost World Souvenir Magazine, 42).

Apatosaurus bones at the Universal Studios Hollywood backlot.

These bones featured around the Worker Village are also used in the Universal Studios Hollywood backlot tour, which uses several leftover props from the first three films including InGen Harvest vehicles, a Fleetwood RV, and the InGen barge that transports Dr. Alan Grant and the Kirby family downstream on Isla Sorna, and pieces from the Pteranodon Aviary. The bones used in the tour were the same bones that Dr. Ian Malcolm, his daughter Kelly, and Dr. Sarah Harding pass when they enter the Village. These bones can also be seen in the TV series Sliders, where the Worker Village set is used in several episodes. These bones anatomically match the caudal vertebrae and ischium and ilium of Apatosaurus.

Further evidence stems from a dinosaur fetus prop from Jurassic Park /// which appears to be an undeveloped, baby Apatosaurus as the neck would grow longer later in life; however, some say this prop looks like a Hadrosaurus. The junior novelization of this book mentions Apatosaurus as one of the dinosaurs seen while the rescue party lands on the island, but this role was given to Brachiosaurus in the final film.

Since all of these films were released before the 2015 split between Apatosaurus and Brontosaurus, it was long assumed that “Apatosaurusexcelsus was the species intended to appear. While this is possibly still the case in these older apatosaurs, the introduction of this species in the flesh with Jurassic World confirms that at least the newer apatosaurs belong to Apatosaurus. The publication that resurrected Brontosaurus was released after the Jurassic World website introduced Apatosaurus, and no change was made before the film was released (nor was this animal’s name updated in the years following). This indicates that the species featured is, in all likelihood, Apatosaurus ajax.

Disambiguation Links

Apatosaurus excelsus (JN)

Apatosaurus excelsus (CB-Topps)

Apatosaurus excelsus (C/N)